Electric switch.



F. L. COLLINS & E. A. HULTS.

ELECTRIC SWITCH.

APPLICATION FILED JUNE 3, 1909.

' Patnted May 17 u fl F. L. COLLINS & E. A. HULTS.

ELEOTEIU SWITCH.

APPLIOATION FILED JUNE 3; 1909'.

Patented May 17,1910. I mums-sum 2.

ANDREW B. BRAMAM 00.. FMOTfl-UTKOGRAPNEFE WASHINGTON. o c

Patented May 17, 1910.

' 4 sums-4911mm a.

F L COLLINS dz E A HULTS ELECTRIC SWITCH. APPLIUATION TILED JUNE 3 1909new l um nom umocmmzas, wAsHmm'w. D. c

F. L. COLLINS & E. A. HULTS.

ELEOTEIO S WITOH. APPLICATION FILED JUNE a. 1909.

958,598. Patented May-17, 1910.

4 SHEETS-SHEET 4.

UNITED STATES PATENT OFFICE.

FRED L. GOLLINS AND EUGENE A. HULTS, OF CHICAGO, ILLINOIS.

ELECTRIC SWITCH.

Specification of Letters Patent.

Patented May 17, 1910.

Application filed June 3, 1909. Serial No. 500,008.

To all whom it may concern:

Be it known that we, FRED L. CoLmNs and EUGENE A. Home, citizens of theUnited States, residing at Cliicag-o, in the county of Cool: and Stateof Illinois, have invented certain new and useful Inqrrovements inElectric Switches, of which the following is a specification.

The object of our invention is to provide a new and improved switch forchanging electric circuit connections. In certain of its aspects, ourinvention is especially adapted for circuits carrying heavy currents ofelectricity.

In the accompanying drawings, we have illustrated one specificembodiment of our invention which is especially adapted to have theswitch terminal-s immersed in oil and in which for illustrativepurposes, the switch is shown in a form adapted for the starting andrunnii'ig positions of an induction motor, as will bemore fullyexplained hereinafter.

The more specific objects of our invention and its advantages willbeeorneepporent on perusal of the following specification and claims,taken in connection with the drawings, in which F i-gure 1 is a frontelevation of the device taken partly in section on the line- 1 in- Fig.4 lookingin the direetionof the arrow. Fig. 2 is a. vertical sectiontaken on the line 2 in Fig. 4. looking in the direction of arrow, Fig..3, is a, partial View corresp nding to Fig. 2., shown-1g certainmovable pertsin a changed relative position. Fig. #l is'e verticalsection taken on the line st in Fi- 1, looking in. the direction of thearrow. iig. 5 is an elevation of an auxiliary device taken partly insection on the line 5 of Fig. 1. Fig. 6 is a diagram. illustratingsuit-able circuit connections for the articular switch which we have.chosen. to s. ow in the draw Lugs.

Thev device compe iseson upper cast. iron shell adapted to be bolted toa: wall by means of the lugs 16, and a lower cast. iron shell: .18adopted. to hose-cured. to the upper shell lfi by means of theimposed-lugs l7 and 19 and the bolts 20I These two shells form a.complete box like housing for the parts within. We make the upper shell3L5 with its front end 15" detachable, as shown n F 1g. 1 the: two parts15 a d 15/ bein cured together by means of the stud! Q111 114', as showninFig. 1. Two opposite brackets or hangers 21, reinforced by ribs 22,project downwardly and inwardly from the wall of the shell 15, theirlower ends carrying the horizontal. flanges 23 to which the slate slab 21 is secured by means of the bolts 26. This slab- 24 has th ree'holes 25through which pass the conductors 109. Attached to the brackets 21, bymeans of the stud bolts 28., are the extension pieces 27 which carryprojecting trunnions 29. These trunnions 29 are rotatably mounted in therespective members 27 and pinned totherespective members 30 and 32. Thehard maple bar Set is secured to the member 3.0 and the walking boa-1n3.2 by means of the respective stud bolts 31 and This bar 3-4 curriescopper sockets 35- in ali-nernent with respective holes 25 in the slateslab 2.4:. The conductors 109 are soldered or sweat-ted into the sockets35-. Eech socket 35 has its lower end tapered and adapted toreceive acorrespondingly tapered sleeve 37, which may be secured. tightly thereby meansoi the stud bolt 38. Each sleeve 37 has an ottset position 3.6.,between which and the maple bar 3.4;, are the copper bars 39-, the steelspring 41 and. the intermediete pring r inforcing h r 4B0, all. thesepar-ts. being secured to the maple bar 3% by means of the bolts 118.

The. ends of the copper bars 39- are ofiset as hidiceted by thereference numeral- 2, bolts l3-possingthrough the ports, as shown inFigs. 2. and By means of. the three nuts on each.- ost these. bolts thecontact torxiii-nails. 4.6 can be adjusted so that all three of th m on.one side w ll act simultane usly. The steel spring; 41 carries. coppercontact terminals 4E6 adopted to coac-t with the.- fined terminals e8.Copper ribbon strips 11.01am rovided connecting the copper her- 4 9 eon.ductivel-y to the contact terminal-s 4.6. Extension springs M areseen-red. under the bolts ,13 and carry supplement ry eel 0on t-actterminal pieces 45, adapted to count with the. steel supplementaryterminals 47.

The fixed contact-terminal pieces 4L8 ere oonnectexiby bolts. .50 andnuts 51,. 5.2- to the. copper members: 49, each of which. is bentupward1y,.as shown Fig. 2; and ear ries a cup 53 to receive the end oftherespective conductor thereto.

The upper shell tront 1.5 has a boss 54 whichcarries erotetable shatt55, to. the in nor end of which: the Walking beam 55 is secured by meansof the key 57 and nut 58. The ends of the two walking beams 57 and 32are connected together by means of the links 59; these connectionscomprising the :5 slots 59 in the Walking beam 32, so as to facilitatemovement of the parts.

Fixed on the shaft is the cam plate and loosely mounted on the shaft 55adjacent to the cam plate 60 is the lever 61 with the handle 65. Theshell member 15 has a notched lug 62 adapted to be engaged by the dog 63controlled by the hand hold 64. The helical tension spring 66 connectsthe arm 68 of the cam plate 60 to the stud 67 on the lever 61. The camplate 60 has the notch 69 on its periphery normally engaged by the dog71 plvoted on the casing at 70. This dog 71 carries an arm 72 adapted tobe engaged by the adjustable stud 74 on the lever 61. This stud can befixed at any desired adjustment by means of the lock nut 75. The dog 71also carries another arm 71 which is engaged by a tension spring 73tending to hold the do 71 against the cam plate 60. A stud 76 pro ectingfrom'thecasing member 15 acts as a stop for the lever 61. On its oposite side, the cam plate 60 has the contour 7 with decreasing radiusgoing around the cam plate in a clockwise direction. The dog 78, pivotedat 79, is held against this cam 77 by means of the tension spring 82,engaging the arm 83. The dog 78 also carries another arm 80 with a hold81 on the end thereof. This arm 80 is adapted to be engaged by theadjustable. stud 87 on the lever 61. At the ends of the cam 77 are thenotches 84 and 85. The stud 86 in the casing plate 15 acts as a stop forthe lever 61.

Pivoted on the bolt 88 is the L-shaped lever 89, one end 90 thereof,resting on the arm 80 of the dog 78, and the other end 91 being bentaround the side of the casing 15 below the solenoids 94. These solenoids94 are within-a hood 92 attached to the casing shell 15 by means of thestud'bolts 93. Each solenoid 94 has a core 95 with a stem 96 assingthrough a hole 98 in the arm 91.

uts 97 have screw threaded engagement with this stem 96, and thusprovide for adjustment. These solenoids 94 and the associated partsconstitute an overload circuit breaker, whose operation will beexplained later.

' In Fig. 6, the three conductors of a three phase transmission circuitare indicated by the reference numeral 99; and 100 is an open deltastartin' transformer from which taps are taken 0 to the five conductors101 as shown. From these taps branch conductors 102, 108, 104, 105 and106 may be taken off to supply an three phase induction motor 107. There erence numeral 108 designates generally the particular switch whichwe have descrlbed as an illustrative embodiment of our invention. Asshown in the diagram, it will readily be perceived that the switch is ina running position, but that by throwing it on the contact terminals ofthe conductors 103, 104 and 106, the motor 107 will then be connected tothe half voltage taps of the starting transformer 100. 111 is a crossconnector from the conductor 104, which clearly shown in Fig. 6.

It will be noted that the shell 18 is in the form of a cup adapted tohold insulating oil, a suitable approximate level for which is indicatedby the reference numeral 112. It will be observed that by removing thebolts 20, this cup 18 can be lowered with its contained oil and setaside, thus making the contact members of the switch readily accessiblefor inspection or repairs.

The switch is shown in F igs, 1 and 2 in neutral open position, and itwill readily be observed on comparing Fig. 2 with Fig. 3 that in closingthe switches on either side, the terminals 45 and 47 will meet first andthen the terminals 46 and 48 will meet, and in all cases, there will bea sliding movement between the pair of terminals, thus keeping thembright and more eflectively excluding oil from between them. Theterminals 4547 meeting first, and breaking last, will always carry theare, thus protecting the main terminals 46 and 48. If for any reason itis necessary to remove the contact terminals for repairs this can veryreadily be done by withdrawing the bolts 28 and 38 and disconnecting thelinks 59 from the walking beam 32; and thus the maple bar 3 can bedirectly removed.

tion; first closing the switch to start an induction motor, thenshifting it to running position, and then restoring it to normal; thiswill sufiiciently illustrate its applicability for other uses. To start,the operator seizes the handle -64 withdrawing the dog 63 and pulls thelever 61 over to the left as viewed in Fig. 1 until the stud 74 strikesthe arm 72 and withdraws the dog 71. This movement of the lever havingextended the spring 66, it follows that as soon as the dog 71 iswithdrawn from the cam plate 60, the tension of the spring 66 willinstantly jerk the cam plate 60 around to the left, as viewed'in Fig. 1.Thereupon the dog 78, influenced by the spring 82, will drop into th8IIQtl1 84 and the circuit contacts will be closed as indicated by Fig.3. The motor will t us s art supplied from the half voltage taps of heopen delta autotransformer 100. As soon as the motor ets to going fastenough, the operator w1ll throw the lever clear over to the right untilthe stud 87 strikes the arm of the dog 78, thus withdrawing it from thenotch 84, and permitting the spring 66 to jerk the cam plate 60 aroundto the right until the dog 78 We will now describe the mode ofoperadrops into the notch 85. This movement of the cam plate '60 willtake place very quickly, and by means of the connecting links 59, themovable switch member Will be quickly reversed from the position shownin Fig. 3, thus cl'ianging to full running 'msition for the motor. Thisclock Wise movement of the cam plate will cause the earn 7 7 to engagethe dog 7 8 and push it back farther until it drops Into the notch 85,the lever 61 mean While resting against the SlXlP 86. When the dog 78has locked into the notch 85, the operator returns the lever (-51 tonormal position locking it there by means of the dog (38, and thusleaving the spring 66 on a tension. Whenever it is desired to stop themotor, this can be accomplished by tripping the dog 78 by means of thehandle 81, thus pern'iitti-ng the spring 6'6 to jerk the cam plate incounter clockwise direction back to the normal position, shown in Fig.1.

In case of an overload, the solenoids 94 will be energized excessivelyand will pull up on their cores 95, thus causii'ig the end 90 of thelever 89 to trip the dog 78 and stop the motor.

It will be seen that We have provided mechanism by which a circuit canbe closed instantly, can be changed as quickly from one arrangement toanother, and can be quickly broken. The mechanism is compara'tivelysimple and is sure in its mode of operation.

The device is automatic in its action; it will be noted that When theswitch is in its nor-marl open position, it cannot be thrown directly tofull running position, but r'n-ust first be thrown to the startingposition. It is further automatic in that quick action is inevitable; itis impossible for an as'tte'ndant to break or make the contacts slowly,even if he tries. This quick act-ion does away with the formation ofinjurious arcs and thus preserves the contact terminals, For

motors of several hundred kilowatts sup plied with current at severalhundred volts, there would be very destructive arcs formed at theterminals, unless they were made or broken almost instantaneously as isthe case in our device. Another point of advantage is that the contactterminals When made are pressed ti'ghtly and firmly together by thesprings 'on Which they are mounted.

By means of the nuts on the bolt 43, the spring 4l can be adjustedrelatively to the ends 120f the bar 39, so as to make the three contactterminals 46 on one side touch their respective 'coacti-ng fixedterminals =18 at the same instant. In this Way, the three circuits aremade and broken exactly simultaneously.

All movable and Wearing par-ts are so arranged that every one can easilyand replaced very little trouble and be gotten at when necessary withtime" All the contact terminals are safely inoloseol in a suitablehousing which is absolutely dust proof. The device can be operated bycom purutively imskilled laborers, and hence the control of large induction motors can be safely entrusted to them. M any other ad'vai'rtageswill. be apparent to those skilled in the art to which this inventionrelates.

In the following c'laii'ns, We ei'nploy the term camdate in a broadsense to refer to the n'iember 60 or its equivalent.

it. An electric s'wito'h con'iprising an upper shell adapted to besupported in a suit.- zrble manner, the front wall of said .s'hell beingremovable, a lower shell adapted to be secured to the upper shell,contact terminals Within the lower shell supported by inside hangersdepending from the upper shell, and mechanism secured to the front wallof the upper shell for operating and coi'itrol'ling said contactterminals, said inechai-iism remaining mounted on said front Wall whenthe latter is removed from the rest of the shell.

2. An electric switch comprising a casing adapted to be supported in asuitable mannor, contact terminals Within the casing, mechanism securedto one outside face of the casing for operating andcon'trolling saidcontact terminals, a handle for actuating said mechanism, an overloadcircuit breaker mounted on another outside face of the casing and havingconnections around the corner of the casing to also actuate saidmechanism, and a hood attached to the casing to protect said overloadcircuit breaker.

An electric switch comprising an upper shell, a lower shell adapted tobe secured thereto, extension brackets hanging down from the upper shellWithin the lower shell, a horizontal slab of insulation attached to thelower ends of said brackets, stationary contact terminals mounted on theunder face of said slab, trunnion's also attached to said brackets, anda member carrying mova ble contacts mounted on said t-runnions.

4. An electric switch comprising an upper shell, a lower shell securedthereto, brackets han in-g down from the upper shell Within the ower shfixed contact terminals supported by $2.1 brackets, trunnions alsosupported by said brackets, and her mounted on said trunnions carryingcontacts adapted to engage the fixed contacts, said member being adi'ustably supported on the lower ends-of said brackets.

5. An electric switch comprising an up:

er shell, a lower shell secured thereto, rackets de end-in Within-theower s e11, fixed contact termina ls supported by said brackets,trunnions carried .by the lower ends of said brackets, a bar pivotallymounted on said trimnions,

a movable memfrom the upper shellflexible contact strips fixed on saidbar and adapted to engage the said fixed contact 1t)erminals, andmechanism to operate said 6. An electric switch comprising an insulatingslab, fixed opposite contact terminals on said slab, an oscillatory barbetween said fixed terminals adjacent to the slab, and flexible contactterminals extending across the bar and adapted to engage the fixedcontact terminals alternatively according to which way the bar isoscillated.

7. An electric switch comprising a horizontal insulating slab withopposed fixed contact terminals on its lower face, a hori zontal barbeneath the said slab mounted to oscillate on its axis, said slab havingholes therethrough above said bar, transverse flexible contact terminalscarried by said bar and adapted to engage the said fixed terminals, andconductors passin through said holes in the slab and connects to saidtransverse contact terminals 8. An electric switch comprising a shelladapted to contain oil, a horizontal insulating slab supported in theoil, fixed contact terminals on the under face of the slab, a movablemember pivotally supported beneath the slab, and coacting movablecontact terminalscarried by said member.

9. An electric switch comprising a fixed contact terminal, a movablemember carrying a coacting terminal, a movable cam plate operativelyconnected to said movable member, a dog on a fixed pivot adapted topositivelyinterlock with said cam plate, an independently movable handlever, a spring connecting the said hand lever to the said cam plate,means to positively withdraw the dog from the cam plate in a certaindefinite position of the hand lever, and means to lock the hand lever ina position to put the said spring on a tension when the dog interlockswith said cam plate.

10. An electric switch comprisinga' fixed contact terminal, a movablemember carrying a contact terminal adapted to coact therewith, a notchedcam plate operatively connected to said movable member, two dogs adaptedto lock positively into the notches of said cam plate, an independentlymovable hand lever,a spring onnection between the cam plate and the ndlever, and means to lock the lever in a position to put the spring on atension when one of the dogs looks into said cam plate.

11. An electric switch com rising an upper and a lower shell adapte tobe secured together, a fixed contact terminal supported in the lowershell, an oscillatory beam mounted in the lower shell and carrying acoaeting contact terminal, a walking beam secured to said oscillatorybeam, another walking beam in the upper shell, links con necting therespective ends of the two walking beams, and mechanism outside of theupper shell to operate the upper beam.

12. An electric switch comprisin an 0scillatory shaft adapted to actuatet e movable coi'itact terminal of the switch, a cam plate fixed on saidshaft, a hand lever loosely mounted on the same shaft, a dog adapted topositively interlock with the cam plate, a spring connecting the saidhand lever and cam plate, means to positively withdraw the dog from thecam plate in a certain definite position of the hand lever, and means tolock the hand lever, in a position to put the said spring on a tensionwhen the dog interlocks with said cam plate. 13. An electric switchcomprising an oscillatory shaft adapted to actuate the movable contactterminal of the switch, a cam plate fixed on said shaft, a hand leverloosely mounted on the same shaft, a dog on a fixed pivot adapted tocoact with the cam plate, a spring connecting the said hand lever andcam plate, said hand lever being adapted in one position to engage thedog thus releasing the cam plate and permitting the spring to actuatethe same, and means to lock the hand lever in a position to extend thespring when the dog engages the cam plate.

14:. An electric switch comprisin an oscillatory shaft adapted toactuate t e mo"- able contact member of the switch, a notched cam platefixed on said shaft, two dogs adapted to coact therewith, a hand leverloosely mounted on the same shaft and 10a adapted in certain positionsto engage the dogs and release the same, a spring connecting the handlever to the cam plate, and means to lock the hand lever in a positionto extend the spring when one of the dogs 105 engages the cam plate.

15. An electric switch comprising an oscillatory shaft adapted toactuate the movable contact terminal of the switch, a notched cam platefixed on the shaft, a 110 dog engaging a notch in the cam plate when theswitch is in open position, a hand lever loosely mounted on the sameshaft, aspiring connecting the hand lever to the cam plate, said leverbeing adapted to disengage the 115 dog from its notch in the cam plateand thus permit the spring to oscillate the same, and means to lock thehand lever in a position to put the spring under tension when the dogengages the cam plate.

16. An electric switch comprising two alternative fixed contactterminals, a movable contact terminal member adapted to engage eitherone of the fixed terminals, an oscillatory shaft controlling saidmovable 125 member, a notched cam plate fixed on the oscillatory shaft,a dog engaging anotch in said cam plate when the switch 1s in neutralposition, and another dog engaging either of two notches in the camplate when the 1:);

switch is in its corresponding closed positions.

17. An electric switch comprising two alternative fixed contactterminals, a movable contact terminal member adapted to engage eitherone of the fixed terminals, an oscillatory shaft controlling saidmovable member, a notched cam plate fixed on the oscillatory shaft, adog engaging a notch in said cam plate when the switch is in neutralposition, another dog enga 'ng either of two notches in the cam p atewhen the switch is in its corresponding closed positions, a hand leverloosely mounted on the oscillatory shaft, and a spring connecting thesame to thecam plate.

18. An electric switch comprising two alternative fixed contactterminals, a movable contact terminal member adapted to engage eitherone of the fixed terminals, an oscillatory shaft controlling saidmovable member, a notched cam plate fixed on the oscillatory shaft, a doengaging a notch in said cam plate when t e switch is in neutralposition, another dog engaging either of two notches in the cam platewhen the switch is in its corresponding closed positions, a hand lever.loosely mounted on the oscillatory shaft, and a sprinj' connecting thesame to the cam plate, sai' lever being adapted to strike against saiddogs thus releasln'g the same and permitting the spring to act upon thecam plate.

19. An electric switch comprising two alternative fixed contactterminals, a movable contact terminal member adapted to engage eitherone of the fixed terminals, an oscillato-ry shaft controlling saidmovable member, a notched cam plate fixed on the oscillatory shaft, adog engaging a notch in said cam plate when the switch is in neutralposition, and another dog engaging either of two notches in the cam latewhen the switch is in its correspon ing closed positions, the radius ofsaid cam plate increasing progressively from one of said last twonotches to the other.

20. An electric switch comprising an oscillatory shaft controlling themovable con tact terminal of the switch, a notched cam plate fixed onsaid shaft, a hand lever loosely mounted on said shaft, fixed stops tolimit the movement of the hand lever, and a dog to coact with thenotched cam plate.

21. An electric switch comprising an oscil latory shaft controlling themovable contact terminal of the switch, a notched cam plate fixed onsaid shaft, a hand lever loosely mounted on said shaft, fixed stops tolimit the movement of the hand lever, and a dog to coact with thenotched cam plate, said lever being adapted to disengage the dog justbefore it strikes against its fixed stop. 4 22. An electric switchcomprisin an osc1llatory shaft controlling the movable contact 'sitionbeing full open, the next position terminal of the switch, a cam platefixed on said shaft, a hand lever loosely mounted on said shaft, meansto lock the hand lever in an intermediate position, and means to lockthe cam plate in a certain position.

28. An electric switch comprising an oscillatory member controlling themovable contact terminal of the switch, a dog to lock this oscillatorymember in certain definite positions, a spring acting upon the oscil-"ator member, hand operated means to with raw the dog, and an overloadcircuit breaker also acting on the same dog to re lease it. '24. Anelectric switch comprising a casing, control mechanism mounted on thefront of the casing, a hand lever to actuate said control mechanism, anoverload circuit breaker mounted on the side of the casing, and operatinconnect-ions extending from said overloa circuit breaker around thecorner of the casing to actuate the same mechanism.

25. An electric switch for starting an induetion motor comprising amovable member carrying contact terminals adapted to be locked in anyone of three positions, one going'that for starting from half voltagetaps, and the third osition that for running at full voltage, anmechanism to constrain the operation of theswit'ch in cyclic order fromone position to the next as named.

26, An electric switch comprising an upper shell, a lower shell securedthereto, integral brackets hanging down from the up per shell within thelower shell, fixed contact terminals supported by said brackets,detachable extension brackets attached to the lower ends of saidintegral brackets, said detachable brackets carrying trunnions, and amember pivoted on said trunnions carrying contacts adapted to engage thesaid fixed contacts.

27 An electric switch for starting a polyphase induction motor comrising a support, a hanger depending there rom, a horizontal slab ofinsulating material attached to said hanger, a member pivotally mountedbeneath the slab, contact terminals carried by said movable memberconductively connected to the motor, and fixed contact terminals mountedon the under face of the slab to cooperate with the movable terminals,said.- fixed terminals being supplied with different voltages, and anoil receptacle inclosmg all said contact terminals.

28. An electric switch comprising a fixed contact terminal, a movablemember carrying a coacting terminal, a movable cam plate operativelyconnected to said movable member, a dog on a fixed pivot, said cam platebeing abruptly notched to receive said dog,

an ifidependently movable hand lever, aspring connecting said cam plateand hand ceases lever, means to withdraw the dog from the abrupt notchin the cam late in a certain definite position of the ban lever, andmeans to lock the hand lever in another definite position.

29. An electric switch comprising a fixed contact terminal, a movablemember carrying a contact terminal adapted to coact therewith, a camplate operatively connected to said movable member, said cam plate having a plurality of abrupt notches therein, two dogs adapted to lock intosaid abru t notches in the cam plate, an independent y movable handlever, a spring connection be tween the cam plate and the hand lever,and means to lock the hand lever in a position to put the spring undertension when one of the do s locks into a notch of the cam plate.

30. 11 electric switch comprising a fixed contact terminal, a movablemember carrying a contact terminal adapted to coact therewith, a camplate operatively connected to said movable member, an abrupt notch insaid cam plate, a dog adapted to lock positively into said abrupt notchin the cam plate, an independently movable hand lever, a springconnection between the cam 'plate and the hand lever, and means to lockthe hand lever in a position to put the spring under tension when one ofthe dogs locks into a notch of the cam plate.

31. An electric switch comprising a fixed contact terminal, a movablemember carry ing a coacting terminal, means to lock the movable memberwith the terminals in engaging position, an independent hand lever, aspring connecting the hand lever to the said movable. member, and meansto lock the hand lever in a position to put said spring on a tensionwhen the contact terminals are locked in engaging position.

32. An electric switch comprising opposite fixed contact terminals, amovable member carrying coacting terminals adapted to engage said fixedterminals alternatively, mechanism to lock said movable member in eitherposition, an independent hand lever, a spring from said hand lever tosaid movable member, and means to lock said hand lever in anintermediate position.

33. An electric switch comprising an oscillatory member controlling themovable contact terminal of the switch, mechanism to lock thisoscillatory member in certain definite positions, a spring acting uponthe oscil' latory member, hand operated means to unlock the saidmechanism, and an overload circuit breaker also adapted to unlock saidmechanism.

In testimony whereof, We have subscribed our names.

FRED L. COLLIN S. EUGENE A. HULTS.

Witnesses:

F. W. JONES, F. C. COLLINS.

